org.glassfish.json.NodeReference Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including
all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and
Jakarta Messaging BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* Copyright (c) 2015, 2017 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package org.glassfish.json;
import javax.json.Json;
import javax.json.JsonArray;
import javax.json.JsonArrayBuilder;
import javax.json.JsonException;
import javax.json.JsonObject;
import javax.json.JsonStructure;
import javax.json.JsonValue;
/**
* This class is a helper class for JsonPointer implementation,
* and is not part of the API.
*
* This class encapsulates a reference to a JSON node.
* There are three types of references.
* - a reference to the root of a JSON tree.
* - a reference to a name/value (possibly non-existing) pair of a JSON object, identified by a name.
* - a reference to a member value of a JSON array, identified by an index.
*
* Static factory methods are provided for creating these references.
*
* A referenced value can be retrieved or replaced.
* The value of a JSON object or JSON array can be
* removed. A new value can be added to a JSON object or
* inserted into a JSON array
*
* Since a {@code JsonObject} or {@code JsonArray} is immutable, these operations
* must not modify the referenced JSON object or array. The methods {@link #add},
* {@link #replace}, and {@link #remove} returns a new
* JSON object or array after the execution of the operation.
*/
abstract class NodeReference {
/**
* Return {@code true} if a reference points to a valid value, {@code false} otherwise.
*
* @return {@code true} if a reference points to a value
*/
abstract public boolean contains();
/**
* Get the value at the referenced location.
*
* @return the JSON value referenced
* @throws JsonException if the referenced value does not exist
*/
abstract public JsonValue get();
/**
* Add or replace a value at the referenced location.
* If the reference is the root of a JSON tree, the added value must be
* a JSON object or array, which becomes the referenced JSON value.
* If the reference is an index of a JSON array, the value is inserted
* into the array at the index. If the index is -1, the value is
* appended to the array.
* If the reference is a name of a JSON object, the name/value pair is added
* to the object, replacing any pair with the same name.
*
* @param value the value to be added
* @return the JsonStructure after the operation
* @throws JsonException if the index to the array is not -1 or is out of range
*/
abstract public JsonStructure add(JsonValue value);
/**
* Remove the name/value pair from the JSON object, or the value in a JSON array, as specified by the reference
*
* @return the JsonStructure after the operation
* @throws JsonException if the name/value pair of the referenced JSON object
* does not exist, or if the index of the referenced JSON array is
* out of range, or if the reference is a root reference
*/
abstract public JsonStructure remove();
/**
* Replace the referenced value with the specified value.
*
* @param value the JSON value to be stored at the referenced location
* @return the JsonStructure after the operation
* @throws JsonException if the name/value pair of the referenced JSON object
* does not exist, or if the index of the referenced JSON array is
* out of range, or if the reference is a root reference
*/
abstract public JsonStructure replace(JsonValue value);
/**
* Returns a {@code NodeReference} for a {@code JsonStructure}.
*
* @param structure the {@code JsonStructure} referenced
* @return the {@code NodeReference}
*/
public static NodeReference of(JsonStructure structure) {
return new RootReference(structure);
}
/**
* Returns a {@code NodeReference} for a name/value pair in a
* JSON object.
*
* @param object the referenced JSON object
* @param name the name of the name/pair
* @return the {@code NodeReference}
*/
public static NodeReference of(JsonObject object, String name) {
return new ObjectReference(object, name);
}
/**
* Returns a {@code NodeReference} for a member value in a
* JSON array.
*
* @param array the referenced JSON array
* @param index the index of the member value in the JSON array
* @return the {@code NodeReference}
*/
public static NodeReference of(JsonArray array, int index) {
return new ArrayReference(array, index);
}
static class RootReference extends NodeReference {
private JsonStructure root;
RootReference(JsonStructure root) {
this.root = root;
}
@Override
public boolean contains() {
return root != null;
}
@Override
public JsonValue get() {
return root;
}
@Override
public JsonStructure add(JsonValue value) {
switch (value.getValueType() ) {
case OBJECT:
case ARRAY:
this.root = (JsonStructure) value;
break;
default:
throw new JsonException(JsonMessages.NODEREF_VALUE_ADD_ERR());
}
return root;
}
@Override
public JsonStructure remove() {
throw new JsonException(JsonMessages.NODEREF_VALUE_CANNOT_REMOVE());
}
@Override
public JsonStructure replace(JsonValue value) {
return add(value);
}
}
static class ObjectReference extends NodeReference {
private final JsonObject object;
private final String key;
ObjectReference(JsonObject object, String key) {
this.object = object;
this.key = key;
}
@Override
public boolean contains() {
return object != null && object.containsKey(key);
}
@Override
public JsonValue get() {
if (!contains()) {
throw new JsonException(JsonMessages.NODEREF_OBJECT_MISSING(key));
}
return object.get(key);
}
@Override
public JsonObject add(JsonValue value) {
return Json.createObjectBuilder(object).add(key, value).build();
}
@Override
public JsonObject remove() {
if (!contains()) {
throw new JsonException(JsonMessages.NODEREF_OBJECT_MISSING(key));
}
return Json.createObjectBuilder(object).remove(key).build();
}
@Override
public JsonObject replace(JsonValue value) {
if (!contains()) {
throw new JsonException(JsonMessages.NODEREF_OBJECT_MISSING(key));
}
return add(value);
}
}
static class ArrayReference extends NodeReference {
private final JsonArray array;
private final int index; // -1 means "-" in JSON Pointer
ArrayReference(JsonArray array, int index) {
this.array = array;
this.index = index;
}
@Override
public boolean contains() {
return array != null && index > -1 && index < array.size();
}
@Override
public JsonValue get() {
if (!contains()) {
throw new JsonException(JsonMessages.NODEREF_ARRAY_INDEX_ERR(index, array.size()));
}
return array.get(index);
}
@Override
public JsonArray add(JsonValue value) {
//TODO should we check for arrayoutofbounds?
// The spec seems to say index = array.size() is allowed. This is handled as append
JsonArrayBuilder builder = Json.createArrayBuilder(this.array);
if (index == -1 || index == array.size()) {
builder.add(value);
} else {
if(index < array.size()) {
builder.add(index, value);
} else {
throw new JsonException(JsonMessages.NODEREF_ARRAY_INDEX_ERR(index, array.size()));
}
}
return builder.build();
}
@Override
public JsonArray remove() {
if (!contains()) {
throw new JsonException(JsonMessages.NODEREF_ARRAY_INDEX_ERR(index, array.size()));
}
JsonArrayBuilder builder = Json.createArrayBuilder(this.array);
return builder.remove(index).build();
}
@Override
public JsonArray replace(JsonValue value) {
if (!contains()) {
throw new JsonException(JsonMessages.NODEREF_ARRAY_INDEX_ERR(index, array.size()));
}
JsonArrayBuilder builder = Json.createArrayBuilder(this.array);
return builder.set(index, value).build();
}
}
}
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